Climate Change: Day 12

October 2, 2014

Last time: Estimating the sensitivity of hurricane intensity to SST. Or, linking MPI theory with observations.

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Today: The oceans are certainly heating up. So are we actually seeing stronger hurricanes?

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Tracks as Grids

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Term Project Datasets

Datasets for term project. I'll continue to post links. You choose one. The posted links are in your notes. Here are some additional ones related to today's topic:

U.S. Hurricane Frequency

Annual Atlantic Hurricane Intensity

Annual Atlantic Hurricane Frequency

Hourly Atlantic Tropical Storms You can download the file. Then read it into R using read.table(). You can't read directly from the URL.

Increasing Intensity

L = "http://myweb.fsu.edu/jelsner/Hint.txt"
H = read.table(L, header = TRUE)
H[1:2, ]

  Year nTS AvgInt MaxInt
1 1851   6   59.8  101.1
2 1852   5   72.7  101.2

library(ggplot2)
ggplot(H, aes(x = Year, y = MaxInt)) +
  geom_point() +
  geom_smooth(method = lm) +
  ylab("Maximum Hightest Intensity (m/s)") +
  theme_bw()

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Lifetime Maximum Intensity

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Sensitivity

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2008 Nature Paper

Get the Track Data

library(repmis)
All = source_DropboxData(file = "NATracks.txt", 
  key = "3q7v1kv2qxyrdtj", 
  sep = " ", 
  header = TRUE)

Compute LMI by Year and storm id

library(dplyr)
df = All %>%
  filter(WmaxS >= 34, SYear >= 1967) %>%
  group_by(SYear, Sid) %>%
  summarize(LMI = max(WmaxS) * .447)

Make the graph

ggplot(df, aes(x = factor(SYear), y = LMI)) +
  geom_boxplot() +
  theme_bw() +
  theme(axis.text.x = element_text(angle = 90, hjust = 1)) +
  xlab("") + ylab("Lifetime Maximum Intensity (m/s)")

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Hurricane Climatology

Nephila clavipes

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